[Hospital medication adherence scale development in cardiovascular disorders]. / Validation d'une échelle de mesure de l'adhésion médicamenteuse cardiovasculaire utilisable en contexte hospitalier.

OBJECTIVES: The consequences of non-adherence to prescribed cardiovascular drugs can be serious, with cardiovascular complications having been reported in both secondary and primary prevention. The objective of this study was to develop a new scale to assess medication adherence in patients with cardiovascular diseases during their hospitalization. METHODS: A cohort of 219 high risk cardiovascular patients was evaluated for this study. Data on reasons for non-adherence were collected using the newly developed Medication Adherence Scale in Cardiovascular disorders (Mascard) and compared with physician assessment during medical consultations and the control of their cardiovascular risk factors. RESULTS: The Mascard consists of 5 items has good psychometric properties and validity and correlated with physician assessment and control of cardiovascular risk factors. CONCLUSIONS: This rapid and easy to use scale may be useful for health care practitioners in their assessment of medication adherence in inpatients with cardiovascular disorders.

[Benefit of a short atherosclerosis prevention program on post-stroke vascular risk reduction]. / Intérêt d'un programme court de prise en charge globale de l'athérosclérose sur la réduction du risque vasculaire à distance d'un infarctus cérébral.

INTRODUCTION: Atherosclerosis is a major cause of ischemic stroke. Despite important therapeutic advances, the risk of recurrence of vascular events remains very high. The partial failure of these strategies is to some extent related to the lack of patient adherence to their treatments and to the fact that therapeutic targets are not reached. The aim of the present study was to evaluate the influence of a short atherosclerosis prevention program on vascular risk reduction in stroke patients. PATIENTS AND METHODS: Ninety-five patients with a first ischemic stroke related to atherosclerosis or with a high vascular risk profile were recruited. Three months later, a global evaluation of the atherosclerotic disease and of the vascular risk factors was performed combined with several education sessions on vascular risk factors and way of life. A follow-up evaluation was performed several months later to investigate the number of vascular events and the vascular risk profile. RESULTS: Median follow-up was 684 days after stroke. At follow-up, 91.3% of patients were taking a cholesterol-lowering drug, 95.6% an anti-thrombotic agent, and 78% an angiotensin converting enzyme inhibitor. A persistent decrease in tobacco use and an improvement in glycemic control were observed. During follow-up, 3.2% of patients died; none of the deaths were related to a vascular event. During the 22-month follow-up, 7.6% of patients experienced a major vascular event, acute coronary syndrome or stroke. CONCLUSION: Compared with results in the literature, this study illustrates the positive influence of a short atherosclerosis prevention program combining depiction of atherosclerotic lesions and education of vascular risk factors on the quality of long-term post-stroke prevention.

Assessing cardiovascular risk factors after coronary artery bypass surgery: value of an aggressive strategy including systematic follow-up.

INTRODUCTION: Coronary revascularization surgery is a palliative treatment modality which should not preclude efforts to treat atherosclerosis. AIM: To assess ongoing cardiovascular risk factors after coronary artery bypass surgery and develop a strategy to attenuate such factors. METHODS: 108 patients requiring a coronary artery bypass were included: 2 died soon after surgery and 6 were excluded for personal reasons. 100 patients were re-admitted into hospital 7 months after surgery for risk factor assessment. Eight months later, they were re-contacted by telephone (systematic follow-up) for a re-assessment. RESULTS: The population consisted of 77 men with an average age of 64+/-11 years. Prior to the operation, the known risk factors were: smoking 34%; HBP 61%; cholesterol 47%; diabetes 30%; obesity 25%. During their hospital stay six months after the procedure: 91% of the patients had at least one lipid metabolism abnormality. New-onset diabetes was diagnosed in 5%. Blood pressure was uncontrolled in 18% and 10% were still smoking. Patients tended to be putting on weight and 55% engaged in little or no physical activity. Systematic follow-up: lipid metabolism had normalized in 70% of the patients. Blood glucose levels were significantly lower. Blood pressure was uncontrolled in 9% and 4% were still smoking. Their weight had stabilized and 65% were engaging in moderate-to-strenuous physical activity. CONCLUSION: Inadequate attention is paid to risk factors after coronary artery bypass surgery. A short hospital stay including a cardiovascular evaluation and education about risk factors has a positive impact on the management of atherosclerosis in the medium term.

[The prevalence of abnormal glucose regulation after myocardial infarction: Comparative study in two French ethnic groups]. / Anomalies du métabolisme glucidique au décours d'un syndrome coronarien aigu : une étude comparative de deux groupes ethniques français.

OBJECTIVES: The aim of this study was to compare the prevalence of abnormal glucose tolerance in patients stemming from two French ethnic groups and admitted for acute coronary syndrome (ACS) to intensive coronary care unit. MATERIALS AND METHODS: During a period of six months, 53 and 60 consecutive patients were enrolled at Fort-de-France (Martinique, French West Indies, Afrocaribbeans, group F) and at Bordeaux (France, Europeans, group B), respectively. Glucometabolic state was classified according to medical history and fasting glycemia measured from the fourth day after ACS. RESULTS: At baseline, 36% of the patients of group F and 20% of the patients of group B had previously known diabetes (p=0.06). Prevalence of hypertension was higher in Afrocaribbeans than in Europeans (60 versus 40%, p<0.05). According to fasting glycemia, newly detected diabetes were found in six Afrocaribbeans and only one was found in Europeans; two patients in group F and three patients in group B displayed impaired fasting glycemia. As a whole, 51% of Afrocaribbeans and 27% of Europeans showed abnormal glucose tolerance (p<0.05). Furthermore, Afrocaribbeans displayed lower levels of triglycerides and higher levels of HDL cholesterol than Europeans (p<0.05). CONCLUSION: Our study suggested a higher prevalence of impaired glucose metabolism in French Afrocaribbeans than in European counterparts after ACS. Furthermore, French Afrocaribbeans displayed a more favorable lipoprotein profile. These characteristics look like that of the American and British Afrocaribbeans, maybe because of a common genetic origin.

Murine models of myocardial and limb ischemia: diagnostic end-points and relevance to clinical problems.

Ischemic disease represents the new epidemic worldwide. Animal models of ischemic disease are useful because they can help us to understand the underlying pathogenetic mechanisms and develop new therapies. The present review article summarizes the results of a consensus conference on the status and future development of experimentation in the field of cardiovascular medicine using murine models of peripheral and myocardial ischemia. The starting point was to recognize the limits of the approach, which mainly derive from species- and disease-related differences in cardiovascular physiology. For instance, the mouse heart beats at a rate 10 times faster than the human heart. Furthermore, healing processes are more rapid in animals, as they rely on mechanisms that may have lost relevance in man. The main objective of the authors was to propose general guidelines, diagnostic end points and relevance to clinical problems.

Kinetics of adventitial repair in the rat carotid model.

BACKGROUND: Discrepancies between success in experimental animals with a variety of pharmacologic strategies and failure with such agents in clinical trials have raised questions concerning the mechanism of restenosis. Recent observations suggest a potential implication for the adventitial (Adv) layer in neointimal formation. METHODS: The purpose of this study was to examine the Adv changes in the rat carotid artery subjected to balloon injury. These changes were characterized by morphometric, immunohistochemical, and electron microscopy analyses, with special attention devoted to early time-points post-injury. RESULTS: We report that the most important adventitial changes occurred in the first 48 h post-injury. Within 2 h there was extensive cell-loss by apoptosis and oncosis in the Adv and in the media; this was followed by the rapid onset of proliferation and a parallel slow increase in Adv thickening, reaching a maximum at 7 days. We further demonstrate an early migration of these Adv cells to the media and neointima. Moreover, we characterize the Adv cell phenotype with a panel of antibodies. Within 48 h after injury, a population of Adv cells expressed alpha-actin and vinculin with a maximum expression 7 days post-injury. At that time, these Adv cells started to express smooth muscle myosin heavy chain, a specific marker of smooth muscle cells. In parallel, we report an impaired production of elastic fibres in the Adv and medial layer. CONCLUSIONS: We reported a detailed time-course of adventitial changes after rat carotid injury (cell death, proliferation, migration and differentiation) that supports an important role of adventitia in neointima formation.

[The mechanisms of angiogenesis. Medical and therapeutic applications]. / Les mécanismes de l'angiogenèse. Applications médicales et thérapeutiques.

PURPOSE: Endothelial and smooth muscle cells interact with each other to form new blood vessels. In this review, the cellular and molecular mechanism underlying the formation of the primary vascular plexus (vasculogenesis), the sprouting of further blood vessels (angiogenesis) and their maturation via recruitment of smooth muscle cells (arteriogenesis) during physiological and pathological conditions are summarized. CURRENT KNOWLEDGE AND KEY POINT: The concept of angiogenesis is studied in tumoral and cardiovascular pathology. Promoting the formation of new collateral vessels in ischemic tissues using angiogenic growth factors (therapeutic angiogenesis) is a promising approach in cardiovascular diseases. Conversely, inhibition of the action of key regulators of angiogenesis is a new pathway for the treatment of solid tumors and metastasis. FUTURE PROSPECTS AND PROJECTS: These concepts are being tested now in clinical trials in the oncology or cardiovascular fields. Some trials are reported in this review with their potential adverse effects, limits and developments in the future.

Short- and long-term risk factors for sudden death in patients with stable angina.

Sudden death is most common and often the first manifestation of coronary heart disease although its risk is difficult to predict. It has been studied mainly in patients with severe ventricular arrhythmia or recent myocardial infarction, but little is known about the different risk factors for short- and long-term risk of sudden death in patients with stable angina. To assess risk factors for sudden death in patients with stable angina and angiographically proven coronary artery disease, 319 consecutive patients were recruited prospectively and followed-up. Patients with clinical heart failure or recent myocardial infarction were excluded. Clinical, angiographic and biological variables were recorded. The association between each variable and the risk of sudden death was assessed in univariate and logistic multivariate analysis. There were 25 sudden deaths during the follow-up period (97+/-29 months). The univariate predictors in the short-term (2 years) were: peripheral arterial disease, left ventricular hypertrophy, low density lipoprotein cholesterol and ejection fraction. The independent predictors were: peripheral arterial disease (relative risk: 6.3), ejection fraction (relative risk 1.05) and low density lipoprotein (relative risk: 1.8). In the long-term (8-10 years), body mass index, coronary score, ejection fraction and fibrinogen were univariate predictors. Only body mass index (relative risk: 1. 2), ejection fraction (relative risk: 1.06) and fibrinogen (relative risk: 2) remained independent predictors. The risk factors for sudden death in stable angina were time-dependent, peripheral arterial disease appeared as the best predictor with LDL for short time, and body mass index (obesity: index >27) and fibrinogen for long time. Ejection fraction was the only time-independent predictor.

Detection of coronary stenoses by stress echocardiography using a previously implanted pacemaker for ventricular pacing: preliminary report of a new method.

BACKGROUND: The number of patients with pacemakers has been increasing and a large number of them will present with chest pain or symptoms suggesting angina pectoris. Myocardial ischemia and presence of coronary artery disease are difficult to detect and assess by noninvasive methods in patients with a pacemaker; the electrocardiogram (ECG) at rest and during exercise is usually very difficult to analyze in terms of ischemia or even presence of an acute myocardial infarction. HYPOTHESIS: To detect significant coronary stenosis in patients with previously implanted pacemakers, we tested a new stress echocardiography method using incremental ventricular pacing by already implanted pacemakers. METHODS: We studied prospectively 25 consecutive patients who underwent stress echocardiography with increasing ventricular pacing up to either 85% of the age-predicted maximal heart rate or chest pain. Positive tests were defined by new hypokinesia or worsening of a preexisting alteration in wall motion in at least two adjacent territories. All patients underwent coronary angiograms to define the presence and severity of coronary stenoses. RESULTS: Among the 25 tests, 11 (44%) were stopped for chest pain. 1 (4%) for moderate discomfort, 1 (4%) for a drop in blood pressure, and the target pacing rate was achieved in the tests of the remaining 12 patients (48%). There were no complications. Thirteen patients had significant stenoses. In 10 cases, stress echocardiography was a true positive test with respect to coronary angiography. There were 11 true negative, 1 false positive, and 3 false negative tests. The sensitivity was 77%, specificity was 90%, the positive predictive value was 91%, and the negative predictive value 79%. The accuracy was 84%. CONCLUSIONS: This new stress echocardiography method appears feasible, easy, safe, and effective for detection of significant coronary stenoses in patients with pacemakers.

Pulmonary embolism revealed on helical CT angiography: comparison with ventilation-perfusion radionuclide lung scanning.

OBJECTIVE: We compared helical CT angiography and ventilation-perfusion radionuclide lung scanning as initial tests in the diagnosis of acute pulmonary embolism. SUBJECTS AND METHODS: Two hundred sixteen consecutive patients who were clinically suspected of having acute pulmonary embolism underwent helical CT angiography, ventilation-perfusion radionuclide lung scanning, and Doppler sonography of the veins of the legs. On the basis of concordance of the results for ventilation-perfusion radionuclide lung scanning and helical CT angiography and on the degree of clinical suspicion, certain patients underwent pulmonary angiography. Patients without pulmonary embolism at initial evaluation in whom no treatment was instituted were followed up for at least 3 months to determine the potential recurrence of thromboembolic disease. RESULTS: Of the 216 patients, 37 (17%) were excluded because of insufficient data to assess the initial event. Final diagnosis for the 179 remaining patients was pulmonary embolism in 68 (37.9%) and no pulmonary embolism in 111 (62.0%), based on pulmonary angiography in 23 patients (12.8%) and concordant imaging findings and outcome in the remaining patients. Statistically significant differences (p < 0.05) were found between sensitivity, specificity, positive predictive value, and negative predictive value for helical CT angiography and ventilation-perfusion radionuclide lung scanning (94.1% versus 80.8%; 93.6% versus 73.8%; 95.5% versus 82%; and 96.2% versus 75.9%, respectively). Interobserver agreement was excellent for helical CT angiography (kappa = 0.72) and moderate for ventilation-perfusion radionuclide lung scanning (kappa = 0.22). CONCLUSION: Helical CT angiography could replace ventilation-perfusion radionuclide lung scanning as the initial test for screening patients who are clinically suspected of having pulmonary embolism.

Expression pattern of mouse sFRP-1 and mWnt-8 gene during heart morphogenesis.

The Wnt genes encode a large family of secreted proteins that play a key role in embryonic development and tissue differentiation in many species (Rijsewijk et al., 1987; Nusse and Varmus, 1992). Genetic and biochemical studies have suggested that the frizzled proteins are cell surface receptors for Wnts (Vinson et al., 1989; Chan et al. , 1992; Bhanot et al., 1996; Wang et al., 1996). In parallel, a number of secreted frizzled-like proteins with a conserved N-terminal frizzled motif have been identified (Finch et al., 1997; Melkonyan et al., 1997; Rattner et al., 1997). One of these proteins, FrzA, the bovine counterpart of the murine sFRP-1 (93% identity) is involved in vascular cell growth control, binds Wg in vitro and antagonizes Xwnt-8 and hWnt-2 signaling in Xenopus embryos (Xu et al. , 1998; Duplàa et al., 1999). In this study, we report that sFRP-1 is expressed in the heart and in the visceral yolk sac during mouse development, and that sFRP-1 and mWnt-8 display overlapping expression patterns during heart morphogenesis. From 8.5 to 12.5 d.p. c., sFRP-1 is expressed in cardiomyocytes together with mWnt-8 but neither in the pericardium nor in the endocardium; at 17.5 d.p.c., they are no longer present in the heart. In mouse adult tissues, while sFRP-1 is highly detected in the aortic endothelium and media and in cardiomyocytes, mWnt-8 is not detected in these areas. Immunoprecipitation experiments demonstrates that FrzA binds to mWnt-8 in cell culture experiments.

[Superiority of second harmonic imaging for echocardiographic measurement of lef ventricular volumes. Comparison with angiocardiography]. / Supériorité de l'imagerie de seconde harmonique pour les mesures échocardiographiques des volumes ventriculaires gauches. Comparaison à l'angiocardiographie.

Analysis of left ventricular volumes is a prognostic factor in cardiovascular disease. Echocardiography is a means of obtaining these parameters but is limited by poor reproducibility. Recently, a new echocardiographic technique, second harmonic imaging (SHI), developed through contrast agent methods, significantly improved the quality of imaging. The aim of this study was to demonstrate the value of SHI for assessing left ventricular volumes. Thirty patients admitted for cardiovascular evaluation and requiring angiocardiography underwent echocardiography with calculation of end diastolic (EDV) and end systolic volumes (ESV) of the left ventricle in fundamental (FI) and second harmonic (SHI) imaging. These measurements were compared with those of angiocardiography. The reproducibility of SHI was calculated after repetition of the measurements by two independent observers for both echocardiographic modes. There was a significant improvement of the parameters of linear regression in SHI compared with FI both for EDV (r = 0.93 versus 0.76) and for ESV (r = 0.94 versus 0.83), the reproducibility was also significantly improved in SHI (relative error of 5% versus 12% for intra-observer error and 6% versus 13% for inter-observer error). The authors conclude that SHI significantly improves two-dimensional imaging and provides a reliable and reproducible measurement of left ventricular volumes.

Impaired collateral vessel development associated with reduced expression of vascular endothelial growth factor in ApoE-/- mice.

BACKGROUND: The impact of disordered lipid metabolism on collateral vessel development was studied in apolipoprotein (apo)E-/- mice with unilateral hindlimb ischemia. METHODS AND RESULTS: Hindlimb blood flow and capillary density were markedly reduced in apoE-/- mice versus C57 controls. This was associated with reduced expression of vascular endothelial growth factor (VEGF) in the ischemic limbs of apoE-/- mice. Cell-specific immunostaining localized VEGF protein expression to skeletal myocytes and infiltrating T cells in the ischemic limbs of C57 mice; in contrast, T-cell infiltrates in ischemic limbs of apoE-/- mice were severely reduced. The critical contribution of T cells to VEGF expression and collateral vessel growth was reinforced by the finding of accelerated limb necrosis in athymic nude mice with operatively induced hindlimb ischemia. Adenoviral VEGF gene transfer to apoE-/- mice resulted in marked augmentation of hindlimb blood flow and capillary density. CONCLUSIONS: These findings thus underscore the extent to which hyperlipidemia adversely affects native collateral development but does not preclude augmented collateral vessel growth in response to exogenous cytokines. Moreover, results obtained in the apoE-/- and athymic nude mice imply a critical role for infiltrating T cells as a source of VEGF in neovascularization of ischemic tissues.

[Double stenosing valve disease after mediastinal radiotherapy: a case report of a 31 year-old man]. / Double valvulopathie sténosante post-radiothérapie médiastinale. A propos d'un cas, chez un homme de 31 ans.

Cardiac complications of radiotherapy for cancer, especially lymphoma and breast cancer, are well documented. The three tunics of the heart can be affected. However, valvular disease is rare and, when present, is usually regurgitant. Stenosis is very rare. The authors report the case of a 31 year old man who developed double mitro-aortic valvular stenosis 20 years after mediastinal radiotherapy associated with aortic regurgitation, right coronary stenosis and inflammatory epicardo-pericarditis with effusion. Surgery was undertaken and associated double aortic and mitral valve replacement and right coronary by pass grafting.

Mouse model of angiogenesis.

Neovascularization of ischemic muscle may be sufficient to preserve tissue integrity and/or function and may thus be considered to be therapeutic. The regulatory role of vascular endothelial growth factor (VEGF) in therapeutic angiogenesis was suggested by experiments in which exogenously administered VEGF was shown to augment collateral blood flow in animals and patients with experimentally induced hindlimb or myocardial ischemia. To address the possible contribution of postnatal endogenous VEGF expression to collateral vessel development in ischemia tissues, we developed a mouse model of hindlimb ischemia. The femoral artery of one hindlimb was ligated and excised. Laser Doppler perfusion imaging (LDPI) was employed to document the consequent reduction in hindlimb blood flow, which typically persisted for up to 7 days. Serial in vivo examinations by LDPI disclosed that hindlimb blood flow was progressively augmented over the course of 14 days, ultimately reaching a plateau between 21 and 28 days. Morphometric analysis of capillary density performed at the same time points selected for in vivo analysis of blood flow by LDPI confirmed that the histological sequence of neovascularization corresponded temporally to blood flow recovery detected in vivo. Endothelial cell proliferation was documented by immunostaining for bromodeoxyuridine injected 24 hours before each of these time points, providing additional evidence that angiogenesis constitutes the basis for improved collateral-dependent flow in this animal model. Neovascularization was shown to develop in association with augmented expression of VEGF mRNA and protein from skeletal myocytes as well as endothelial cells in the ischemic hindlimb; that such reparative angiogenesis is indeed dependent upon VEGF up-regulation was confirmed by impaired neovascularization after administration of a neutralizing VEGF antibody. Sequential characterization of the in vivo, histological, and molecular findings in this novel animal model thus document the role of VEGF as endogenous regulator of angiogenesis in the setting of tissue ischemia. Moreover, this murine model represents a potential means for studying the effects of gene targeting on nutrient angiogenesis in vivo.

Effects of poloxamer 407 on transfection time and percutaneous adenovirus-mediated gene transfer in native and stented vessels.

UNLABELLED: Reduction in transfection time and the ability to perform gene transfer in conjunction with endovascular stent implantation constitute two important challenges for percutaneous adenovirus-mediated gene transfer to vessel walls. Studies have suggested that the use of biocompatible polyol poloxamer 407 could be useful. We first evaluated the use of poloxamer 407 for percutaneous gene transfer in nonstented rabbit iliac arteries. A 200-microl mixture of Ad-RSVbetagal or Ad-CMVLuc in either phosphate-buffered saline (PBS) or 20% poloxamer was delivered. After 3 days, gene transfection was evaluated by X-Gal staining or measurement of luciferase activity. Poloxamer use resulted in a 3- to 15-fold increase in the percentage of transfected cells (X-Gal, p = 0.001) and a 16-fold increase in protein product (luciferase activity, p = 0.03), and allowed a decrease in transfection time from 30 to 5 min with minimal reduction in transfection efficiency. We then evaluated the feasibility of percutaneous gene transfer, using Ad-RSVbetagal diluted in pure PBS or 20% poloxamer, in conjunction with stent implantation. Gene delivery was performed either immediately before (pre-) or after (post-) stent implantation. When adenoviruses were diluted in PBS, gene transfer had a low efficiency (prestent, 0.3%; poststent, 0.2%; NS). With poloxamer, the efficacy was much higher (p = 0.0001) and similar "pre" (2.2%) or "post" (1.7%) stent delivery (NS). CONCLUSIONS: (1) The use of poloxamer, rather than PBS, as a vehicle increases the efficacy of percutaneous adenovirus-mediated gene transfer and reduces transfection time; (2) gene transfer performed during stent implantation with poloxamer is feasible and achieves a significant level of gene expression. Thus percutaneous gene delivery is applicable to conventional stents and could present an attractive method by which to achieve local biological effects in a stent environment.

Reciprocal relation between VEGF and NO in the regulation of endothelial integrity.

Balloon angioplasty disrupts the protective endothelial lining of the arterial wall, rendering arteries susceptible to thrombosis and intimal thickening. We show here that vascular endothelial growth factor (VEGF), an endothelial cell mitogen, is upregulated in medial smooth muscle cells of the arterial wall in response to balloon injury. Both protein kinase C (PKC) and tyrosine kinase pp60src mediate augmented VEGF expression. In contrast, nitric oxide (NO) donors inhibit PKC-induced VEGF upregulation by interfering with binding of the transcription factor activator protein-1 (AP-1) to the VEGF promoter. Inhibition of VEGF promoter activation suggests that NO secreted by a restored endothelium functions as the negative feedback mechanism that downregulates VEGF expression to basal levels. Administration of a neutralizing VEGF antibody impaired reendothelialization following balloon injury performed in vivo. These findings establish a reciprocal relation between VEGF and NO in the endogenous regulation of endothelial integrity following arterial injury.

Restenosis or rapid progression in non-dilated sites are not predictors of late spontaneous coronary events.

The present study was designed to assess the prognostic value of clinical and angiographic factors, and especially restenosis or rapid progression in non-dilated sites, on major spontaneous coronary events at long-term follow-up after a first successful coronary angioplasty performed for angina pectoris. A second aim was to assess the prognostic factors and especially restenosis in asymptomatic patients after angioplasty. The first 352 consecutive patients undergoing a successful coronary angioplasty were selected and followed-up. The following variables: age, sex, unstable angina, previous myocardial infarction, diabetes, hypercholesterolemia, tobacco consumption, hypertension, fibrinogen, coronary extent, single or multiple dilatation, restenosis, new progression, clinical deterioration of anginal status just before angiographic restudy or asymptomatic status were subjected to a stepwise regression analysis. Restenosis (a loss of 30% in diameter and/or a return to a >50% stenosis) and progression in non-dilated segments (a 20% reduction in diameter) were assessed by a computer-assisted method. Cardiac death, new myocardial infarction or new unstable angina, at long-term follow-up after angiographic restudy, were regarded as spontaneous coronary events and pooled in a single dependent variable. Thus 41 patients had a coronary event. In the overall population, clinical deterioration of anginal status (p<0.001, relative risk: 3.65) and fibrinogen (p<0.05, relative risk: 1.03) were independent predictors of spontaneous coronary events. Restenosis or new progression were not predictors. In asymptomatic patients (n=187), fibrinogen (p<0.01, relative risk=1.06) was the only predictor and restenosis was not an independent predictor of spontaneous coronary events. The best predictor of spontaneous coronary events at long-term follow-up after a first successful coronary angioplasty is clinical deterioration in anginal status in the months following the procedure. Restenosis does not appear as an independent predictor. Rapid progression observed in non-dilated sites is not an important prognostic factor.

Vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) in normal and atherosclerotic human arteries.

Vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) is an endothelial-cell-specific mitogen; as such, its role in angiogenesis has been studied extensively. VEGF/VPF may also serve as a local, endogenous regulator of large-vessel endothelial cell integrity. Surprisingly, however, VEGF/VPF expression in normal and/or atherosclerotic vessels has not been previously characterized. Accordingly, we studied normal human arteries and veins as well as atherosclerotic and restenotic human coronary arteries for evidence of VEGF/VPF expression. VEGF/VPF was detected immunohistochemically in sections of normal human aorta, mammary artery, and saphenous vein. Moreover, VEGF/ VPF expression was identified in 32 (97%) of 33 pathological coronary arterial specimens; the extent of VEGF/VPF staining was graded as moderate to strong in 21 of the 32 (66%) positive specimens. VEGF/VPF double immunostaining and in situ hybridization demonstrated that smooth muscle cells constitute the principal cellular source of VEGF/VPF. VEGF/VPF immunostaining among primary atherosclerotic lesions localized predominantly to the extracellular matrix. In restenotic specimens, VEGF/VPF immunostaining was more prominently cellular, particularly among proliferating smooth muscle cells. Although VEGF/VPF expression was observed in areas of macrophage infiltration, double immunostaining failed to localize VEGF/VPF to macrophages in these foci; instead, double immunostaining clearly identified CD45RO-positive cells as responsible for VEGF/VPF expression in such areas. No correlation could be demonstrated between VEGF/VPF immunostaining and extent of vasa vasorum. These findings thus establish that postnatal VEGF/VPF expression is a feature of normal human arteries and veins and is often extensively expressed in arteries narrowed by atherosclerotic plaque. VEGF/VPF expression in the wall and/or plaque of medium to large vessels suggests a role for VEGF/VPF other than promoting angiogenesis. This role may involve maintenance and repair of luminal endothelium.

Histochemical staining following LacZ gene transfer underestimates transfection efficiency.

Analysis of LacZ gene expression is conventionally inferred from blue staining that results from exposure of the transfected cells or tissue to the substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). Such histochemical staining reports not whether the gene product is present or absent, but where it is active. We investigated the hypothesis that identification of activity, as opposed to presence, of the enzyme underestimates gene expression following LacZ gene transfer. Under conditions optimized for in vitro histochemistry, up to 20% of cells stably transfected with nls-LacZ remained unstained by X-Gal. In contrast, immunostaining with a monoclonal or a polyclonal anti-beta-galactosidase (beta-Gal) antibody positively stained 99% of the cell nuclei. Following in vivo transfection of naked DNA encoding for nls-LacZ, X-Gal staining disclosed 2.7 +/- 1.7 positive nuclei per LacZ-transfected animal, or a transfection efficiency of 0.015%. In contrast, immunohistochemical staining disclosed 118 +/- 32.7 positive nuclei per transfected animal, yielding a transfection efficiency of 0.64% (p < 0.0001 versus X-Gal staining). Thus, 42.9 times more positive cells were detected by antibody than X-Gal staining. Finally, LacZ gene expression following intramuscular gene transfer with an adenoviral vector was observed in 7.6% of skeletal muscle cells assessed with X-Gal; anti-beta-Gal antibody identified 21.8% of cells as being successfully transfected (p < 0.0001). Thus, X-Gal histochemistry following gene transfer of constructs encoding LacZ may underestimate the anatomic extent of gene expression. The superior sensitivity of immunostaining suggests that anti-beta-Gal antibody represents the preferred analytical tool for light microscopic evaluation of LacZ gene transfer.